Wireless digital networks, such as networks operating under the current Electrical and Electronics Engineers (IEEE) 802.11 standards, are spreading in their popularity and availability. Conventionally, on mobility controllers with Virtual Local Area Network (VLAN) pool configuration in Virtual Access Point (VAP), wireless stations are assigned with a VLAN identifier based on a number of algorithms in a station management module (STM), such as, the HASH algorithm, the EVEN algorithm, etc. However, the HASH algorithm can oversubscribe any one DHCP pool and thus fail to assign Internet Protocol (IP) address to station while other DHCP pools have available addresses in the pool.
The EVEN algorithm attempts to perform load balancing across VLAN assignments. However, in an environment with multiple controllers in the WLAN, each controller may not have an overall view of the network. Thus, if the same DHCP pool is being used by multiple controllers, there can be situations where the assigned VLAN to a station does not have any available IP address in its DHCP pool, whereas some other VLAN in the VLAN pool has IP address available in its DHCP pool.
In general, both the EVEN algorithm and the HASH algorithm of VLAN assignment have problems, with which associating client device might not be able to obtain an available IP address from a DHCP pool corresponding the client device's assigned VLAN.